Voltage regulators, such as DC-to-DC voltage converters, are used to provide stable voltage sources for various electronic systems. Efficient DC-to-DC converters are particularly needed for battery management in low power devices (e.g., laptop notebooks, cellular phones, etc.). A switching voltage regulator generates an output voltage by converting an input DC voltage into a high frequency voltage, and then filtering the high frequency input voltage to generate the output DC voltage. Specifically, the switching regulator includes a switch for alternately coupling and decoupling an input DC voltage source (e.g., a battery) to a load (e.g., an integrated circuit (IC)). An output filter, typically including an inductor and a capacitor, may be coupled between the input voltage source and the load to filter the output of the switch, and thus provide the output DC voltage. A controller (e.g., a pulse width modulator, a pulse frequency modulator, etc.) can control the switch to maintain a substantially constant output DC voltage.
Conventional isolated power supplies can include one or more primary switches, at least one power transformer, and at least one rectifier on a secondary side. A power transformer is used to provide a relatively large voltage conversion ratio, a more robust short circuit protection on an input source, and both primary and secondary isolation to conform to certain power regulations. The rectifier may be used to rectify an AC voltage and/or current waveform output from a transformer secondary winding into a DC voltage and/or current to supply an output load.